It is well known to weld together two sheets of metal using a resistance welding unit. Welding electrodes are applied to opposite sides of the metal panels and current is conducted through the electrodes to weld and fuse the panels together and form a spot weld. Over time the welding electrodes wear and must be replaced.
Accordingly it is well known that the welding electrode include a shank that is connected to the resistance welder to receive the weld current, and a replaceable weld cap, typically of copper alloy, that is either press fit or threaded onto or into the shank to permit removal and replacement of the worn weld cap.
It is also well known that the efficiency of the resistance welding process is improved by circulating a coolant, such as water, through the shank to cool the weld cap. The heat is transferred from the weld cap into the coolant and then carried away.